having the skill to assemble it means nothing. You should have perfected the design from shapeways separately from your own print material. If I can't get it functionally assembled, the design isn't good enough to account for either the use of shapeways material or the variance in it. And trust me, I have more than enough "skill as a craftsman".
The shapeways material has far too much friction to allow the action to work. There is also too much allowance in the slider plate to prevent the hammers from flying together underneath the plate, even while screwed together. I made a completely new (and perfect) slider out of aluminum, and it's almost sufficient to allow the design to work. Still, there is too much friction with this material, and I cannot help but wonder how that happened. Did you test them before putting them up for sale, using the shapeways prints? somewhere along the way, there was a disconnect, and being that I'm one of the ones (and no, I'm not alone) who's out $140 or whatever it was, I am quite upset by it. the shapeways material isn't the only problem either. The parts don't clear each other and lock back together like they should. They interfere with each other too much, and as a result, they prevent anything in the mechanism from working without applying an understanding of DAOTF mechanisms and modifying it as such.